acp³U: A Conserved RNA Modification with Lessons Yet to Unfold

RNA modifications are highly conserved across all domains of life, suggesting an early emergence and a fundamental role in cellular processes. The modification 3-(3-amino-3-carboxypropyl)uridine (acp³U) is found in tRNAs of eukaryotes and prokaryotes, and in the 16S rRNA of archaea. In eukaryotic rRNA, a complex modification containing the acp group, m